Alternate realities

The Big House is one of four specialized, high security prisons maintained by S.H.I.E.L.D. along with Vault, The Cube, and The Raft. Designed by Hank Pym and held aboard the S.H.I.E.L.D. Helicarrier. Both the Big House and it's prisoners were shrunk down by using Pym Particles, so that they are infinitely more easy to handle. Pym designed it in mind to house criminals whose genome has been altered and offer them rehabilitation.[2]